have 84 300d turbo it was getting sluggish so i put new injector nozzles in injectors it is much better power wise on highway but always a but . on idle engine shakes like its skipping engine did not have that issue before . i got inj pressures close to2000 psi . do inj pressure have to be exactly the same . i fitted monarc nozzles . anyone have idea why thats the case

Find the one that's the culprit loosen the hard lines one at a time to find it you'll know!
See how it sprays and then fix it.

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92 e300d2.5t
01 e320
05 cdi
85 chev c10

I seem to remember the spec being 1950-2000 psi. Unless you're very patient when lapping the bodies it's just luck if they are within 10 psi of one another.

dieselbenz1 has given you the quickest method to assess the problem. When you find the culprit and tear it down look for dirt or any contamination and make sure the assembly is clean.

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84 300SD
85 380SE
83 528e
95 318ic

Do you have a nozzle tester/pop tester?

Since someone has already spoken about the injectors no need to repeat that.

Also, as the timing chain sketches, wears and gears wear the timing becomes retarded/late. Increasing the injector opening pressure makes the timing a slight bit later.

Adjusting the fuel injection pump timing normally takes care of that.

If you wanted to go deeper into it you can check the timing chain stretch and if that needs correcting with an offset woodruff key after that time the fuel injection pump.

Former owners of these cars often don't know that the valve clearances need to be adjusted. If they have been out of adjustment for a long time when they are readjusted, they need to be driving say 300 miles and the adjustment re-checked.

What does the see-through plastic filter look like? Are you seeing air bubbles moving through it? Is there any blackish greenish gray substance inside of the filter?

If you have one that can be taking apart the fuel pressure relief/overflow valve springs usually become compressed over time. The manual allows that you can remove the plug on it and take out the spring and the ball bearing that is used as a valve. You can stretch the spring till it has a free length of 27mm.

The one that you cannot take apart has a ball bearing pressed into it.

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84 300D, 82 Volvo 244Gl Diesel

If you have an MW fuel injection pump there is also an adjusting screw on it to reduce the hot idle shaking but it only dose that a bit.

Usually, they need to be replaced and the adjustment procedure followed.

Some people also have set their idle speed too slow. There is a sticker that has what your idle speed is supposed to be. On mine it is on the left side top of the front radiator support. In the yellow circle on the attached pic.

You are supposed to back off that screw and adjust the idle speed with the normal idle speed screw that is on the engine side of the fuel injection pump and then slowly turn in the rack damper/governor idle pin screw till you remove a bit more engine shaking. You are supposed to remove as much shaking as you can without effecting the idle speed.

Also, the Engine and transmission are suspended on 2 engine/motor mounts and one rear transmission mount. If they are collapsed it is going to shake at idle speed.
Use only quality motor mounts.

Attached Thumbnails

 

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84 300D, 82 Volvo 244Gl Diesel

i will have to pull them again.. and try to get them more even. it was fine before i changed them just sluggish. the valve lash i checked about two months ago its been so cold recently i put off doing it. thanks to everyone for helping

Geroid ;

You neglected to answer D911's important questions .

If the injectors all pop within 14# of each other, look for 'drooling' ~ this is dripping of fuel before they pop off .

Also, it's critical they all have a perfect symmetrical , cone shaped fan of fuel spray ~ NO DROPLETS .

Many years ago a nice local guy who had his own pop tester and shim filing set up, took my crappy old injectors and cleaned them then set to spec, the only problem was : they squirted like tiny fire hoses .

Oddly enough the car then started easily in 40* F temps and didn't smoke , got 25 + MPG's but it wasn't right and he never grasped why not .

The Details are where you get easy starting even in cold weather .

Mercedes says if it's under 50* F to cycle the glow plugs twice then hold the accelerator to the flor and crank it until all cylinders are firing ~ DO NOT let off the key until you hear all five cylinders firing and the engine speed begins to rise ~ the internal governor will prevent you from over speeding or damaging .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better